While the Darwinian evolutionary principle of "survival of the fittest

Kaplan's Explanation

Problem 1 -
Which of the following, if true, would most support the scientists' hypothesis?
(A) The longer a brown anole stayed in the cage in the characterization phase of the experiment, the more likely that anole would be to hide from a predator in the wild.
(B) Some brown anoles have a prominent orange crest that is highly visible to curly-tailed lizards and other predators.
(C) Male brown anoles are less likely to be risk-averse than are female brown anoles.
(D) During breeding season, brown anoles are more vulnerable to predators due to their mating displays.
(E) Female brown anoles will not risk their own lives to protect their eggs or offspring from predators.

Analyze the question stem This is a Strengthen question that asks for evidence to support the scientists' claim that their hypothesis is correct.
Research the relevant text
The hypothesis is given at the end of the second paragraph; the scientists thought that risk-averse brown anoles would have a higher survival rate than risk-prone anoles. First risk aversion was determined, and then survival rate was measured. Risk-averse anoles were defined as those that hide when encountering predators; for the experiment, this was measured by determining how long it took for a brown anole to leave its cage after viewing a predator. The third paragraph discusses the results; the experiment showed that risk aversion did correlate with survival rate for females, not for males.
Make a prediction One weakness in the scientists' findings is that risk-averse behavior helped only the females, so the correct answer might explain why risk-averse behavior doesn't help the males. That is, evidence that shows that hiding would help the males if not for some other, sex-related factor would support the hypothesis that risk-averse behavior promotes survival.
Alternatively, since the experiment measured risk aversion in a way that is different from how it is defined in the hypothesis (by letting the lizards view predators from the safety of cages instead of making them escape predators in the wild), it may also explain how those two measures are equivalent.
Evaluate the answer choices
(A) is correct; it indicates that the measurement of risk aversion the scientists used does in fact correlate with risk aversion in the wild.
(B) may be tempting because it provides a reason that risk aversion doesn't help some brown anoles survive: they can't hide their crest. However, this choice does not specify that it's the males that have this crest, so it doesn't support the scientists' hypothesis.
(C) might seem like it provides a reason that male and female brown anoles have different survival rates. The hypothesis, though, does not depend on how likely brown anoles are to be risk-averse; it focuses on whether those that are risk-averse have a higher survival rate.
(D) is incorrect because it does nothing to connect risk aversion to survival rate.
(E) explains another way in which female brown anoles avoid risks and perhaps indicates that more females than males would be characterized as risk averse. However, it does nothing to explain why risk-averse females have a higher survival rate than risk-averse males.
TAKEAWAY: There may be more than one way to strengthen a claim. Before evaluating the answer choices, consider the different links in the argument's chain of reasoning and think about what evidence would strengthen each.

2) According to the passage, which of the following is true about brown anoles?

A) Brown anoles are native to the Bahamas.
B) A low level of risk aversion provides no benefit to brown anoles.
C) Threat response behavior varies among brown anoles.
D) The brown anole's main threat response strategy is hiding.
E) The curly-tailed lizard is the primary predator of brown anoles.

Analyze the question stem
This asks for something the passage tells you about brown anoles, so it's a Detail question.
Research the relevant text Paragraphs 2 and 3 both talk about brown anoles, so researching both of them would likely not be an efficient use of time. Instead, be ready to research each choice as needed.
Make a prediction Similarly, a specific prediction isn't possible since the passage provides a number of facts about the brown anole. Instead, keep in mind the scope and purpose(to explain an experiment testing the effect of risk aversion on survival rates) as you evaluate each choice.
Evaluate the answer choices
(C) is correct. Risk aversion is described as a threat response strategy, and paragraph 2 describes two levels of risk aversion among brown anoles.
(A) is incorrect because the passage doesn't state whether brown anoles are native to the Bahamas; rather, it only states that the Bahamas were used as a setting for this experiment. The passage states that a high level of risk aversion is correlated with a higher survival rate. However, that doesn't mean that a low level of risk aversion has no benefit at all; it may help in other ways.
Eliminate (B).
(D) is too extreme; hiding is one strategy used by brown anoles to avoid predators, but it's possible they use other strategies.
(E) is similarly too extreme. While the curly-tailed lizard was deployed as the predator in this experiment, it may be that the brown anole has other predators in a more typical habitat that hasn't been swept by a hurricane. TAKEAWAY: Extreme answers are common in Inference questions, but they can also show up in Detail questions. Don't pick an extreme answer unless the information in the passage supports that level of certainty.


3) It can be inferred from the passage that the author would be likely to agree with which of the following statements about the experiment's results?

A) The results support the scientists' hypothesis more than they undermine it.
B) The results of this experiment contradicted those of previous laboratory experiments.
C) The results would have been more accurate had the scientists used a species native to the islands.
D) Potentially inconclusive results can still have value in science.
E) Risk aversion in brown anoles has no effect on their survival.

Analyze the question stem This asks for something the author would be likely to agree with, and it points you in a specific direction; the correct answer will describe the author's opinions of the experiment's results.
Research the relevant text The results of this experiment are described in the third paragraph. In the last sentence of this paragraph, the author injects his opinion, returning to the theme introduced in the first paragraph of the scientists' "clever thinking" by praising the "opportunistic methodology" of their experiment. The scientists think the results support their hypothesis, but the words "either way" at the beginning of the last sentence indicate that the author is withholding judgment on this matter.
Make a prediction Look for an answer that conveys the idea that whether or not the results were conclusive, the experiment was worth conducting.
Evaluate the answer choices
(D) matches the prediction; the results may be inconclusive, but they have value.
(A) and (E) are both wrong for the same reason; they impute too certain an opinion to the author. The author isn't sure that the results support the scientists' hypothesis, but he's also not sure that the experiment showed that risk aversion has no effect on survival.
(B) is incorrect because these results aren't compared to those of other experiments; furthermore, according to the first paragraph, it would be virtually impossible to run this experiment into a laboratory.
(C) is wrong because the author never opines on whether there was a better way for this experiment to be run. Indeed, the author is complimentary about the experiment.
TAKEAWAY: When the correct answer must reflect the author's opinion, avoid choices that reflect someone else's opinion. Researching what the author thinks and holding that prediction firmly in mind will help you eliminate incorrect choices.

4) Based on the passage, which of the following can be inferred about Darwinian principles?

A) "Survival of the fittest" applies only to physical characteristics.
B) Threat response behavior may be subject to evolutionary selection.
C) There is no way to evaluate evolutionary principles in a laboratory setting.
D) The principle of "survival of the fittest" applies to both physical and behavioral characteristics.
E) The response of most behavioral traits to evolutionary selection can be experimentally evaluated.

Analyze the question stem This asks for something that can be inferred, so it's an Inference question.
Research the relevant text The correct answer will be a fully supported statement about Darwinian principles, which are explicitly mentioned in the first paragraph. Make a prediction The first paragraph says that while Darwinian principles were thought to apply only to physical characteristics, they're thought to apply to behavior as well. Furthermore, while it's hard to test behavioral evolution, some scientists have designed an experiment to test one aspect of behavior.
Look for a choice that makes one of these points.
Evaluate the answer choices
(B) is correct; it states that Darwinian principles may affect behavioral traits. Note that this is correct because of the word "may"; anything more certain wouldn't be supported. (A) distorts information from the passage. The author doesn't say that Darwinian principles don't apply to non-physical traits; the author just says that this idea can be hard to test.
(C) also distorts the passage. There's no indication that it's difficult to test all evolutionary principles. While it's "virtually impossible" to test the relationship between evolutionary principles and behavior in a laboratory, it may be easier to test other areas of evolution.
(D) is extreme. Only one behavioral trait was tested, so this broad statement that evolutionary principles apply to behavioral characteristics in general is unsupported.
(E) is wrong for similar reasons; the passage shows only how one specific behavior can be evaluated in an experiment. This may not be possible for other behaviors.
TAKEAWAY: For Inference questions, beware of answer choices that are too broad. The correct choice will reflect what the passage says and not go beyond that.